The Existence of Intermetallic Compounds in the Vapour State. The Spectra of the Alkali Metals, and of their Alloys with Each Other

摘要: It has been uncertain until recently, whether any of the many intermetallic compounds which have established in liquid and solid alloys can persist into vapour state, or they invariably dissociate mere mixtures individual metal vapours. Volatile occasionally suspected ( e. g ., between magnesium zinc) on account deposition typical crystals during distillation an alloy two metals, but such evidence is so indirect that it carries little weight. The most promising way approaching this question by a study absorption spectra metallic metals are known to possess measurable proportion diatomic polyatomic molecules state indicate property appearance bands their spectra. In fact, since accepted band cannot originate from single atoms, observation become delicate test for existence association For example, usual methods molecular weight determination led belief alkali vapours solely monatomic. This cannot, however, be true, as each these possesses extensive spectrum, appears at quite low pressures. There no doubt, basis spectroscopic evidence, appreciable fraction boiling sodium, etc., di- (or poly-) atomic. point will discussed fully below.